This invention generally relates to improving fire suppression systems and techniques and, more particularly, to integrated controls for a fire truck water pump and/or a drive transmission for a fire truck to reduce the occurrence of human error and to improve the efficiency of extinguishing fires.
Fortunately, over the past 20-30 years, the total number of structural fires per year has declined. However, the total number of firefighter deaths and the amount of money lost as a result of fires has not experienced the same decline. In fact, approximately the same number of firefighters die per 100,000 structural fires currently as in years past. As there may be many reasons for this increase in firefighter casualties, one cited problem is a lack of real world experience for firefighters due to fewer occurrences of fires. While increasing the frequency of training is, of course, part of the solution, additional training alone will probably not solve all of these problems. Training inexperienced firefighters on emergency procedures and operations does not truly mimic the urgent, often confused and conflicting information present at an evolving emergency scene.
At a typical fire, quick and efficient pump and foam system operations are a necessity and are not something to be left to chance, particularly in view of the real possibility of human error. Unfortunately, human error is most likely to occur when time is most critical, that is when the fire truck first arrives at the scene of the fire and the pump must be set up. Another factor in the effectiveness of fire suppression is that the size of fire-fighting crews has been noticeably downsized in recent years, due in part to economic conditions. In some areas, fire-fighting crews that previously included 4, 5 or 6 firefighters have been reduced to only 2 or 3 individuals in recent years. Due to such manpower decreases, each firefighter must be as effective and as efficient as possible. It is often the case that the initial actions of the fire-fighting crew on the scene of a fire can determine the entire success or failure of the operation. Therefore, removing non-value added tasks and the associated opportunities for defect or error can be a real improvement in the effectiveness of firefighters.
In conventional plumbing assemblies for fire trucks or other fire suppression systems, water supplied from a water source, such as a fire hydrant fills a supply hose and is forced to the truck. Air that is initially enclosed within the empty supply hose is pushed ahead of the water and up to a master intake valve. If the master intake valve is opened without “bleeding”, or removing the air in front of the water, the pump momentarily becomes “air-bound” and the engine controller speeds up. Once the air is pushed past the impeller of the pump, the pressurized water from the hydrant hits the impeller at elevated engine speeds and a dangerous pressure spike can occur.
Further, conventional fire trucks or other fire suppression systems include a fire pump panel that allows a firefighter to select the exact system parameters for which to fight the fire, such as pump speed and pressure, foam type and foam-to-water ratio. In operation, the firefighter is required to independently select the pump pressure or speed, then independently select the foam type, turn the foam on to release the foam into the water flow, and finally select the desired foam percentage in relation to the water flow. As is well known by those skilled in the art, this process can be relatively time consuming in an emergency and may prevent the firefighter from focusing on more critical needs. Also, this multiple selection process provides an opportunity for human error in selecting the wrong operating settings, especially if the firefighter is relatively inexperienced and is facing high stress due to the emergency situation.
In addition, the typical fire truck pump engagement sequence is an area that can cause problems for a firefighter in an emergency. Traditionally, the pump of a fire truck or other fire suppression system is driven by a power take-off from the truck engine. Engagement of the pump typically requires that the firefighter shift the fire truck transmission to “neutral”, then engage the pump transmission, verify that the shift has been properly completed, and finally place the transmission back into “drive.” Further, once the fire has been extinguished and it is time to leave the scene, the firefighter must place the truck transmission into “neutral”, allow the driveshaft to stop rotating, then shift the pump transmission out of “drive” so that the truck can be driven again. If the firefighter does not properly complete either of these sequences in the correct order, the gears of the fire truck could clash and grind. Obviously, grinding damages the transmission and potentially renders the fire truck inoperable. Additionally, this process may waste valuable time in an emergency.
Therefore, it would be desirable to create an automated tank-to-hydrant change-over process to ensure correct control of the incoming water supply to the fire suppression system or fire truck. Specifically, it would be desirable to allow the firefighter to automatically bleed or remove the air in front of the water inside the supply hose with the push of a single button, such that a pressure spike at the impeller is avoided. Further, it would be desirable to provide a firefighter with the opportunity to chose from at least two predetermined established conditions of flow and pressure for the water and foam to meet the specific requirements of each fire. Furthermore, it would be desirable to provide an interlock that provides a one-touch activated shift sequence. Specifically, it would be desirable to provide an interlock that automatically ensures that the parking brake is on and that the truck transmission is in “neutral” before making the pump shift and returning the fire truck transmission to “drive.”